Manufacture of soap bars or tablets



Patented May 4, 1 954 MANUFACTURE OF SOAP BARS OR TABLETS FrederickOliver James, West Kirby, England, assignor to Lever Brothers Company,New York, N. Y., a corporation of Maine N Drawing. Application April 21,1950, Serial No. 157,410

Claims priority, application Great Britain July 19, 1949 18 Claims.

The present invention relates to the manu facture of soap bars ortablets. More particularly, it relates to the manufacture of hard,filled soaps containing relatively low percentages of total fattymatter.

In the manufacture of soap, hot molten soap may be cooled by passing it,in a fluid condition, as a very thin layer over a strongly cooledsurface whereby it is caused to solidify and crystallize practicallyinstantaneously throughout its entire thickness. It is appropriatelyremoved, from the surface by scrapers or equivalent means. Thesolidified soap thus obtained may be molded or compressed into bars ortablets by the aid of a plodder. Such treatment may be applied to soapcontaining from about 60% to 63% of fatty acids or fatty and resinousacids, or may be applied to filled soaps which contain more than thenormal quantity of water as well as salts such as sodium silicate,sodium carbonate I filled soap may be rapidly chilled and thereafter thesolidified filled soap may be plodded.

At relatively high total fatty matter levels within this range, such asfrom 45% to 60%, the more conventional liquid fillers such as neutralsodium silicate or mixtures thereof with caustic alkalies, alkalicarbonates and water in suitable proportions can be mixed with 63% soapmade from relatively hard fat charges, such as charges containing, e.g., 90% palm oil and palm kernel oil, to produce firm plodded filledsoaps. Weak solutions of salt or other electrolyte may also be used asfillers when the total fatty matter content is above 50% However, whenthese conventional liquid fillings are used in the preparation ofplodded filled soaps containing relatively low percentages of totalfatty matter or plodded filled soap made from softer fat charges, theresultant soap bars and tablets are found to be too soft forsatisfactory handling.

It has now been found that it is possible to produce a plodded filledsoap having relatively lower total fatty matter levels, or made fromsofter fat charges, which is hard enough for satisfactory handling. Thisis accomplished, in

accordance with the invention, by adding sodium aluminum silicate gel tohot molten soap. The soap, which may then have a total fatty mattercontent of between about 30% and is then rapidly chilled and thesolidified soap is thereafter plodded.

The sodium aluminum silicate gel may be added to the soap in a number ofdifferent ways. One such way is to add the sodium aluminum silicate gel,in an already prepared form, directly to the soap. Another way is toform the sodium aluminum silicate gel in situ within the soap. This maybe accomplished, for example, by adding sodium silicate solution andsodium aluminate solution to the hot molten soap, or by adding therequired proportions of such ingredients as aluminum silicate gel oralumina gel, silica gel and caustic soda to form a sodium aluminumsilicate gel of the desired composition.

The proportion of sodium silicate added may be between 3 and 40 partsand that of sodium aluminate between 1 and 10 parts, in which case theamount of soap will vary between 50 and 96 parts.

The resultant soap may contain up to 50% of sodium aluminum silicategel.

One advantage of my invention is that the molten filled soap remainsrelatively fluid for processing purposes.

Another advantage is that I am able to produce a filled soap which, dueto the filling, has base exchange and water softening properties.

Moreover, the product in bar form is quite firm without being overloadedwith solid mat rial.

Furthermore, my novel soap has a good appearance and is relatively freefrom the undesir able phenomenon of efflorescence, which in most filledsoaps is exhibited in various forms ranging from a white bloom to awhiskery or thick furlike surface deposit.

The alkalinity of the filled soap according to the present invention canbe controlled by the relative proportions of the added ingredients. Formany purposes it is desirable to avoid excessive alkalinity in the soap.When this object is in view, it is preferred to use a sodium aluminatewith a NazO/AlzOs ratio of not greater than 1.5 and a neutral sodiumsilicate with a SiOz/NazO ratio of 3.2, all such ratios being understoodto be molecular proportions. In the mixture of sodium aluminate andneutral sodium silicate, the final SiOa/NazO ratio should preferably notbe substantially less than 1.9 unless rather alkaline products arerequired. The siOz/NazO number of ways, two of which are shown by way ofillustration below:

Percent Percent 62% soap 63 63 Neutral sodium silicate, 80 Twaddell 2727 Sodium aluminate solution 40% Nero/A1203 ratio 1.46 10 Sodiumalumlnate 95% New/A1 03 ratio 1.27.

Water used to dissolve the aluminatc o Various examples of proceduresfor carrying out the invention will now be described.

Example 1 63 parts by weight of a 63% total fatty acids content soapmade from a fat charge consisting of 90% palm oil and. 10% palm kerneloil were added to a crutc'h'er in the molten state. Twentyseven parts byweight of 80 Twaddell neutral sodium silicate and 10 parts by weight ofa 40% aqueous solution of sodium aluminate having a NazO /Al2O3 ratio of1.46 were added to the crutcher.

lC'he molten filled soap so obtained therefore contained about 40% totalfatty matter. It was chilled on a refrigerated drum to C. in the matterof a few seconds, milled and then plodded under vacuum. The resultantbars of filled soap were of good appearance and much harder than ploddedfilled soap which contained no sodium aluminum silicate gel and weresimilar in hardness to 63% soap bars prepared by the analogous steps ofchilling, milling and vacuum plodding.

Example 2 63 parts by weight of a molten 63% total fatty acids contentsoap made from a fat charge consisting of 80% palm oil and 20% groundnutoil were mixed in a crutcher with 27 parts by weight of 80 Twaddellneutral sodium silicate and 10 parts by weight of a aqueous solution ofsodium aluminate having an Na'ZO/AIZOS ratio of 1.46. The temperature ofthe molten mixture was 80 'C. The mixture was then chilled to 22 C. inabout 1 second over a three-roll, water-cooled mill, Ire-milled over thesame mill and plodded under vacuum. The bars of filled soap thusobtained contained 41.3% total fatty matter and were of good appearanceand somewhat harder than 63%soap bars prepared in a similar mannerExample 3 The method of Example 1 was repeated, the v amounts of 63%soap, neutral sodium silicate and sodium aluminate being changed,however, to 55,

v 35 and 10 parts by weightyiespectiizely.

The resultant molten filled soap,.which conin a filled soap bar ofsimilar hardness to that .of the soap produced in Example 1.

4 Example 4 The method of Example 2 was repeated, the amounts of 63%soap, neutral sodium silicate and sodium aluminate solution beingchanged, however, to 84, 11.7 and 4.3 parts by weight respectively.

The resultant molten filled soap was subjected to chilling, milling andplodding as in Example 2. The filled soap bar contained 54.8% totalfatty matter and was appreciably harder than 63% soap bars prepared bythe analogous steps of chilling, milling and vacuum plodding.

Example 5 Sixty-nine parts by weight of a 63% total fatty acids contentsoap made from a fat charge consisting of 95% palm oil and 5% rosin weremixed in a crutcher with 22.5 parts by weight of '80 Twaddellneutralasilicate and 8.5 parts by weight of a 40% aqueous solution of95% sodium aluminate of NazO/AhOs ratio 1.27. The molten filled soapthus obtained at a temperature of 83 C. was chilled in about 1 second to22 C. over a three-roll, water-cooled mill and then plodded undervacuum. The bars or filled soap thus obtained contained 45.9% totalfatty matter and were of good appearance and substantially equal inhardness to 63% total fatty matter soap bars prepared in a similarmanner.

Example 6 A mixture was made, at a temperature of 76 0., of 27 parts byweight of 80 Twaddell neutral sodium silicate and 10 parts by weight ofa 40% aqueous solution of sodium aluininate having a NazO/Alzoa ratio of1.46. The mixture was stirred until it formed a slurry which was thenadded to 63 parts by weight of a molten 63% soap made from a fat chargecensisting of 9 0% palm oil and 10% palm kernel oil. The mixture wascrutched at a temperature of 80 C. for 20 minutes, chilled to 24 C. inabout 1 second over a three-r011 Water-cooled mill, milled over athreeroll mill and plodded under vacuum. The bars of filled soap soproduced contained 42.3% total fatty matter and were of good appearanceand substantially equal in hardness to plodded 63% soap bars.

One or more steps may be taken to increase the degree to which thefilled soap mass is compacted during plodding. For example, the filledsoap may be worked prior to plodding,

the said working being carried out by milling or refining. Again theplodding may be carried out at subatmospheric pressure or in thepresence of carbon dioxide. The steps taken to increase the degree towhich the filled soap mass is compressed may also include the step ofpassing the extruded filled soap bar into an extension tube added to thenozzle of the plodder, the increased resistance of which serves to buildup the pressure in the plodder.

The sodium aluminum silicate filler used in my invention may be usedalone or in conjunction with other fillers such as sodium carbonate,starch, sugar, clay and other well-known filler materials.

It is to be expressly understood that the fore going examples are by wayof illustration only and that the invention may be modified in numerousways obvious to those skilled in the art without departing from thescope of the invention as defined in the appended claims.

I claim:

1. A method :of forming a hard solid filled soap product which includesthe steps of chilling hot molten filled soap containing sodium aluminumsilicate gel and thereafter plodding the resultant solidified filledsoap.

2. A method of forming a hard solid filled soap product which includesthe successive steps of forming sodium aluminum silicate gel in situwithin hot molten soap, chilling the molten filled soap and plodding theresultant solidified filled soap.

3. A method of forming a hard solid filled soap product which includesthe successive steps of adding up to about 50% by weight of sodiumaluminum silicate gel to hot molten soap, chilling the molten filledsoap and plodding the resultant solidified filled soap.

4. A method of forming a hard solid filled soap product which includesthe successive steps of adding to hot molten soap about 3 to 40 parts byweight of 80 TW, neutral sodium silicate having a SiOz/NazO ratio of notsubstantially less than 3.2 and about 1 to parts by weight of 40%aqueous sodium aluminate, chilling the molten filled soap and ploddingthe resultant filled soap.

5. A method of forming a hard solid filled soap product which includesthe successive steps of adding to hot molten soap about 1 to 10 parts byweight of 40% aqueous sodium aluminate having a NazO/AlzOs ratio of notgreater than about 1.5 and about 3 to 40 parts by weight of 80 Tw.neutral sodium silicate, chilling the hot molten filled soap andplodding the resultant filled soap.

6. A method of forming a hard solid filled soap product which includesthe successive steps of adding to hot molten soap sodium silicate havinga SiO2/NazO ratio of not substantially less than 3.2 and sodiumaluminate having a Na-zO/AlzOa ratio of not greater than about 1.5 toform a sodium aluminum silicate having a SiO'z/Na2O ratio notsubstantially less than 1.9, chilling the hot molten filled soap andplodding the resultant filled soap.

'7. A method of forming a hard solid filled soap product which includesthe successive steps of adding about 3 to 40 parts by weight of 89 'Iw.neutral sodium silicate and about 1 to 10 parts of 40% aqueous sodiumaluminate to about 50 to 96 parts of hot molten soap, chilling the hotmolten filled soap and plodding the resultant solidified filled soap.

8. A method of forming a hard solid filled soap product which includesthe successive steps of chilling hot molten filled soap containingsodium aluminum silicate gel, working the resultant solidified filledsoap and plodding the worked solidified filled soap.

9. A method as claimed in claim 8 in which the solidified filled soap isworked by milling.

10. A method of forming a hard solid filled soap product which includesthe steps of chilling hot molten filled soap containing sodium aluminumsilicate gel and thereafter plodding the resultant solidified filledsoap at sub-atmospheric pressure.

11. A method as claimed in claim 10 in which the resultant solidifiedfilled soap is worked prior to plodding.

12. A method of forming a hard solid filled soap product which includesthe successive steps of chilling hot molten filled soap containingsodium aluminum silicate gel, milling the resultant solidified filledsoap and plodding the milled. filled soap at subatmospheric pressure.

13. A method of forming a hard, solid, filled soap product whichincludes the successive steps of adding about 3 to 40 parts by weight ofTw. neutral sodium silicate and about 1 to 10 parts of aqueous sodiumaluminate to about to 96 parts of hot molten soap to form sodiumaluminum silicate gel in situ within the hot molten soap, chilling themolten filled soap, and plodding the resultant solidified filled soap.

14. A plodded filled soap containing sodium aluminum silicate gelprepared by the method of claim 1.

15. A plodded filled soap containing up to about 50% sodium aluminumsilicate gel prepared by the method of claim 1.

16. A plodded filled soap containing sodium aluminum silicate gel havinga SiO2/N312O ratio not substantially less than 1.9 prepared by themethod of claim 1.

17. A plodded filled soap containing about 4 to 50 parts of sodiumaluminum silicate gel per about 50 to 96 parts of soap prepared by themethod of claim 1.

18. A hard plodded filled soap containing from about 30 to about byweight of total fatty matter and up to about 50% by weight of sodiumaluminum silicate gel prepared by the method of claim 1.

References Cited in the file of this patent UNITED STATES PATENTS

13. A METHOD OF FORMING A HARD, SOLID, FILLED SOAP PRODUCT WHICHINCLUDES THE SUCCESSIVE STEPS OF ADDING ABOUT 3 TO 40 PARTS BY WEIGHT OF80* TW. NEUTRAL SODIUM SILICATE AND ABOUT 1 TO 10 PARTS OF 40% AQUEOUSSODIUM ALUMINATE TO ABOUT 50 TO 96 PARTS OF HOT MOLTEN SOAP TO FORMSODIUM ALUMINUM SILICATE GEL IN SITU WITHIN THE HOT MOLTEN SOAP,CHILLING THE MOLTEN FILLED SOAP, AND PLODDING THE RESULTANT SOLIDIFIEDFILLED SOAP.